Field of the Invention
The present invention relates to a running gear unit for a rail vehicle comprising a running gear frame body defining a longitudinal direction, a transverse direction and a height direction. The frame body comprises two longitudinal beams and a transverse beam unit providing a structural connection between the longitudinal beams in the transverse direction, such that a substantially H-shaped configuration is formed. Each longitudinal beam has a primary suspension interface section associated to a free end section of the longitudinal beam and forming a primary suspension interface for a primary suspension device connected to an associated wheel unit. Furthermore, each longitudinal beam has a pivot interface section associated to the primary suspension interface section and forming a pivot interface for a pivot arm connected to the associated wheel unit. The primary suspension interface is configured to take a total resultant support force acting in the area of the free end section when the frame body is supported on the associated wheel unit. The invention furthermore relates to a rail vehicle unit with a running gear unit according to the invention.
Description of Related Art
Such a running gear frame is, for example, known from DE 41 36 926 A1 (the entire disclosure of which is incorporated herein by reference). This running gear frame, due to its specific design of the support on the wheel units (such as wheel pairs or wheels sets etc.) is particularly well suited for the use in low floor vehicles, such as tramways or the like. However, due to this support using a horizontally arranged primary spring resting against a pillar element which is considerably retracted in the longitudinal direction with respect to the pivot interface, the running gear frame has a very complex, multiply branched geometry. Hence, just like for many other structural components for rail vehicles, the production of the running gear frame known from DE 41 36 926 A1, not least due to its comparatively complex geometry, is performed by welding sheet material. This production method, however, has the disadvantage that it requires a relatively large percentage of manual labor, which makes the production of running gear frames comparatively expensive.
Furthermore, on the one hand, the pillar element and the horizontally arranged primary spring require comparatively much building space. Since, typically, the building space budget available in a running gear (for receiving the plurality of components required in modern rail vehicles) is heavily restricted, such a configuration is less favorable. This is not least due to the fact that more effort has to be taken to fit all the necessary components into the limited building space available which, ultimately, adds to the overall cost of the vehicle. In addition, the pivot arm itself is of comparatively complex and heavy design, thereby also adding to the overall complexity, the weight and, ultimately, to the overall cost of the vehicle.